Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare this as a non-read-only, non-idempotent, non-destructive write, so the safety profile is covered. The description adds genuine behavioral context by clarifying the draft is not an approved commitment until approve_milestones, which is a meaningful lifecycle trait not present in annotations or schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences with the core action front-loaded and the lifecycle caveat second; nothing is redundant or padded. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be explained, and annotations cover safety. But for a write tool with three undocumented, schema-coverage-0% parameters, the description should clarify at least the role of 'reference'; the parameter gap leaves an agent under-informed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the full burden for three required parameters. It only vaguely implies clientName and projectTitle via 'one client project' and says nothing about the 'reference' string or the formats/constraints of any field.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a concrete verb and resource ('Open a draft milestone set for one client project') and distinguishes the draft state from an approved commitment. It does not fully differentiate itself from siblings like define_milestone or list_milestone_sets, and the verb 'open' is slightly ambiguous versus a plain create.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It points to approve_milestones as the step that turns drafts into commitments, giving implied workflow context. However, it never states when to call this versus define_milestone, save_acceptance_criterion, or list/read variants, so the agent must infer placement in the flow.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.